Thiopheneazo dye based on a coupling component of the thiazole series

ABSTRACT

Thiopheneazo dyes of the formula ##STR1## where R 1  is cyano, C 1  -C 4  -alkoxycarbonyl, phenylazo, phenylsulfonyl, formyl or the radical ##STR2##  where R 7  and R 8  are independently of the other cyano or C 1  -C 4  -alkoxycarbonyl, 
     R 2  is C 1  -C 4  -alkyl, phenyl, halogen, C 1  -C 4  -alkoxy or C 1  -C 4  -alkoxycarbonyl, or R 1  and R 2  together are the radical (CH 2 ) 3  --CO, which may be substituted by 1 or 2 methyl groups and whose carbonyl group is bonded to the thiophene ring in the ortho position relative to the sulfur atom, 
     R 3  is cyano or C 1  -C 4  -alkoxycarbonyl, 
     R 4  is C 1  -C 8  -alkyl, cyclohexyl, phenoxy-C 1  -C 4  -alkyl, substituted or unsubstituted phenyl, or substituted or unsubstituted thienyl, 
     R 5  is C 1  -C 4  -alkyl, C 3  -C 7  -alkyl whose alkyl chain is interrupted by 1 or 2 oxygen atoms, or C 1  -C 4  -alkoxy and 
     R 6  is cyanoethyl, phenylethyl or C 3  -C 12  -alkyl whose alkyl chain is interrupted by from 1 to 4 oxygen atoms and which may be substituted by phenyl or phenoxy, 
     with the proviso that, when R 5  and R 6  are each oxygen-interrupted alkyl, R 6  has 2 or more carbon atoms more than R 5 , are used for dyeing textile fibers.

This application is a continuation of application Ser. No. 07/407,282, filed on Sep. 14, 1989, now abandoned.

The present invention relates to a novel thiopheneazo dye of the formula I ##STR3## where R¹ is cyano, C₁ -C₄ -alkoxycarbonyl, phenylazo, phenylsulfonyl, formyl or the radical ##STR4## where R⁷ and R⁸ are identical or different and each is independently of the other cyano or C₁ -C₄ -alkoxycarbonyl,

R² is C₁ -C₄ -alkyl, phenyl, halogen, C₁ -C₄ -alkoxy or C₁ -C₄ -alkoxycarbonyl, or R¹ and R² together are the radical (CH₂)₃ --CO, which may be substituted by 1 or 2 methyl groups and whose carbonyl group is bonded to the thiophene ring in the ortho position relative to the sulfur atom,

R³ is cyano or C₁ -C₄ -alkoxycarbonyl,

R⁴ is C₁ -C₈ -alkyl, cyclohexyl, phenoxy-C₁ -C₄ -alkyl, substituted or unsubstituted phenyl, thienyl, C₁ -C₄ -alkylthienyl or halothienyl,

R⁵ is C₁ -C₄ -alkyl, C₃ -C₇ -alkyl whose alkyl chain is interrupted by 1 or 2 oxygen atoms, or C₁ -C₄ -alkoxy and

R⁶ is cyanoethyl, phenylethyl or C₃ -C₁₂ -alkyl whose alkyl chain is interrupted by from 1 to 4 oxygen atoms and which may be substituted by phenyl or phenoxy,

with the proviso that, when R⁵ and R⁶ are each oxygen-interrupted alkyl, R⁶ has 2 or more carbon atoms more than R⁵, and to use thereof for dyeing textile fibers.

EP-A 269,953 already discloses azo dyes whose diazo components are derived from an aminothiophene and whose coupling components are derived from thiazole derivatives. However, it has been found that the compounds mentioned therein are defective in their application properties.

It is an object of the present invention to provide novel azo dyes based on a diazo component of the thiophene series and a coupling component of the thiazole series, which have an advantageous application profile.

We have found that this object is achieved by the thiopheneazo dye of the formula I defined at the beginning.

All the alkyl groups appearing in the abovementioned formula I can be not only straight-chain but also branched.

If substituted phenyl groups appear in the abovementioned formula I, suitable substituents are for example C₁ -C₄ -alkyl, C₁ -C₄ -alkoxy, halogen, in particular chlorine or bromine, C₁ -C₄ -alkanoylamino, sulfamoyl, C₁ -C₄ -monoalkylsulfamoyl or C₁ -C₄ -dialkylsulfamoyl, where the alkyl chain may be interrupted by an oxygen atom.

Suitable radicals R¹, R² and R³ are for example methoxycarbonyl, ethoxycarbonyl, propoxycarbonyl, isopropoxycarbonyl, butoxycarbonyl or sec-butoxycarbonyl.

R¹ is also for example CH═C(CN)₂, CH═C(CN)COOCH₃, CH═C(CN)COOC₂ H₅, CH═C(COOCH₃)₂ or CH═C(COOC₂ H₅)₂.

R² is also for example, like R⁴ and R⁵, methyl, ethyl, propyl, isopropyl, butyl, isobutyl or sec-butyl.

R² is also for example, like R⁵, methoxy, ethoxy, propoxy, isopropoxy, butoxy, isobutoxy or sec-butoxy.

R² is also for example chlorine or bromine.

R⁴ is also for example pentyl, isopentyl, neopentyl, tert-pentyl, hexyl, isohexyl, heptyl, octyl, 2-ethylhexyl, phenoxymethyl, 2-phenoxyethyl, 2-, 3- or 4-methylphenyl, 2-, 3- or 4-methoxyphenyl, 2-, 3- or 4-chlorophenyl, 2,4-dichlorophenyl, 2-, 3- or 4-bromophenyl, 2-, 3- or 4-formylaminophenyl, 2-, 3- or 4-acetylaminophenyl, 3- or 4-sulfamoylphenyl, 3 l- or 4-monomethyl- or 3- or 4-dimethyl-sulfamoylphenyl or 3- or 4-[bis(2-methoxyethyl)sulfamoyl]phenyl.

R⁵ is also for example, like R⁶, 2-methoxyethyl, 2-ethoxyethyl, 2-propoxyethyl, 2-isopropoxyethyl, 2-butoxyethyl, 2- or 3-methoxypropyl, 2- or 3-ethoxypropyl, 2- or 3-propoxypropyl, 2- or 3-butyoxypropyl, 2- or 4-methoxybutyl, 2- or 4-ethoxybutyl, 2- or 4-propoxybutyl, 3,6-dioxaheptyl, 3,6-dioxaoctyl, 4,8-dioxanonyl, 3,7-dioxaoctyl, 3,7-dioxanonyl, 4,7-dioxaoctyl or 4,7-dioxanonyl.

R⁶ is also for example 2- or 4-butoxybutyl, 4,8-dioxadecyl, 3,6,9-trioxadecyl, 3,6,9-trioxaundecyl, 3,6,9,12-tetraoxatridecyl, 3,6,9,12-tetraoxatetradecyl, 3-benzyloxypropyl, 6-phenoxy-4-oxahexyl, 2-cyanoethyl or 2-phenylethyl.

Preference is given to a thiopheneazo dye of the formula I where only one of R¹, R² and R³ is C₁ -C₄ -alkoxycarbonyl.

Particular preference is given to a thiopheneazo dye of the formula I where

R¹ is cyano, C₁ -C₄ -alkoxycarbonyl or formyl,

R² is C₁ -C₄ -alkyl or chlorine,

R³ is cyano,

R⁴ is phenyl, 2-thienyl or 3-thienyl,

R⁵ is C₁ -C₄ -alkyl and

R⁶ is C₃ -C₉ -alkyl whose alkyl chain is interrupted by from 1 to 3 oxygen atoms and which may be substituted by phenoxy.

In a particularly noteworthy thiopheneazo dye of the formula I, R⁶ is C₂ H₄ OCH₃, C₃ H₆ OCH₃, C₃ H₆ OC₂ H₅, C₃ H₆ OC₂ H₄ OC₂ H₅, C₃ H₆ OCH(CH₃)CH₂ OCH₃, CH₂ (C₂ H₄ O)₂ CH₃, CH₂ (C₂ H₄ O)₃ CH₃, C₃ H₆ O(C₂ H₄ O)₂ C₂ H₅ or C₃ H₆ OC₂ H₄ OC₆ H₅.

The thiopheneazo dye according to the invention is prepared in a conventional manner. For example, a 2-aminothiophene of the formula II ##STR5## where R¹ R² and R³ are each as defined above, can be diazotized and coupled with a thiazole of the formula III ##STR6## where R⁴ R⁵ and R⁶ are each as defined above.

2-Aminothiophenes of the formula II are already known and described for example in EP-A-150,034 or can be obtained in similar fashion to the method of preparation described therein.

The thiazoles of the formula III are in general likewise known compounds. They are described for example in U.S. Pat. No. 3,770,719 and in J. V. Metzger, Heterocyclic Compounds--Thiazole and its Derivatives, vol. 34, part 1, Interscience Publishers, John Wiley, New York, 1979, or can be obtained in similar fashion to the methods described therein.

Further details of the preparation of the dye according to the invention may be found in the Examples.

In general, a thiopheneazo dye of the formula I where R⁵ and R⁶ together have 4 or more oxygen atoms is liquid at room temperature.

The novel thiopheneazo dye of the formula I is advantageously suitable for use as a disperse dye for dyeing textile fibers, in particular cellulose esters or polyesters, but also polyamides or blend fabrics from polyesters and cellulose fibers.

The dyeings obtained have good fastness properties, in particular good light fastness and good fastness to dry heat setting and pleating. The novel dye has good migration properties.

To obtain a favorable color buildup, it can be advantageous in some cases to use a mixture of more than one dye of the formula I according to the invention for dyeing.

The Examples which follow will illustrate the invention in more detail.

EXAMPLE 1

18.7 g of 2-amino-3-cyano-4-chloro-5-formylthiophene where introduced into a 0° C. mixture of 111 g of 80% strength by weight sulfuric acid, 15 ml of glacial acetic acid and 32 g of 42% strength by weight nitrosylsulfuric acid. This was followed by stirring at 0°-5° C. for 4 hours. The diazonium salt solution was then added to a mixture at 0° C. prepared from 36.4 g of a coupling component of the formula ##STR7## 200 g of glacial acetic acid, 40 g of propionic acid and 30 ml of 10% strength by weight amidosulfuric acid solution. After the two solutions had been combined, about 160 g of ice were added, and the mixture was then buffered with sodium acetate solution (about 30% strength by weight) to pH 0.2-0.7. The dye formed was then precipitated in full by the addition of water, filtered off with suction, washed until neutral and dried. This gave 52 g of dark blue powder of the formula ##STR8## The dye forms a blue solution in acetone and dyes polyethylene terephthalate fabric in bright medium blue shades of excellent buildup potential. The dyeings have high light fastness properties and a high fastness to dry heat setting and pleating. λ_(max) : 604 nm (9:1 v/v N,N-dimethylformamide/glacial acetic acid).

EXAMPLE 2

A mixture of 110 g of 80% strength by weight sulfuric acid, 15 g of glacial acetic acid and 32 g of 42% strength by weight nitrosylsulfuric acid was cooled down to 0° C. 21 g of ethyl 2-amino-3-cyano-4-methylthiophene-5-carboxylate were then sprinkled in with thorough stirring and cooling at such a rate that the reaction temperature was maintained at 0°-5° C. Stirring for 3-4 hours gave a clear diazonium salt solution. It was added to a solution prepared from 36.4 g of the coupling component of the formula ##STR9## in 15 ml of concentrated hydrochloric acid, 350 ml of water and 0.5 g of an acidic dispersant. Before the diazonium salt solution was added, 300 g of ice were added to bring the temperature down to ≦0° C., and 1 g of amidosulfuric acid was added. At the same time as the diazonium salt solution water and ice were added in such a way that the coupling mixture stayed stirrable and does not exceed 5° C. The mixture was subsequently stirred for 15 minutes, the pH of the suspension was then raised to 0.5-0.8 by the addition of ice-cold dilute sodium hydroxide solution, and the product obtained was isolated as described in Example 1. This gave 57.5 g of violet powder of the formula ##STR10## which gives a reddish blue solution in acetone and dyes polyester fabric in light-fast, deep reddish blue to navy shades. λ_(max) : 576 nm (9:1 v/v N,N-dimethylformamide/glacial acetic acid).

The dyes listed in the tables below are obtained in a similar manner.

                                      TABLE 1                                      __________________________________________________________________________      ##STR11##                                                                     Ex.                                                                            No.                                                                               R.sup.1   R.sup.2                                                                           X          R.sup.5 R.sup.6   Hue                               __________________________________________________________________________      3 CN        CH.sub.3                                                                          H          CH.sub.3                                                                               C.sub.3 H.sub.6 OC.sub.2 H.sub.4                                               OCH.sub.3 reddish blue                       4 CN        CH.sub.3                                                                          H          C.sub.2 H.sub.5                                                                        C.sub.3 H.sub.6 OC.sub.2 H.sub.4                                               OCH.sub.3 reddish blue                       5 CN        CH.sub.3                                                                          p-OCH.sub.3                                                                               C.sub.2 H.sub.5                                                                        C.sub.3 H.sub.6 OC.sub.2 H.sub.4                                               OCH.sub.3 navy                               6 CN        CH.sub.3                                                                          H          C.sub.2 H.sub.5                                                                        (C.sub.2 H.sub.4 O).sub.2 CH.sub.3                                                       reddish blue                       7 CN        CH.sub.3                                                                          H          C.sub.2 H.sub.5                                                                        (C.sub.2 H.sub.4 O).sub.3 CH.sub.3                                                       reddish blue                       8 CN        CH.sub.3                                                                          H          C.sub.2 H.sub.5                                                                        (C.sub.2 H.sub.4 O).sub.2 C.sub.2                                              H.sub.5   navy                               9 CN        CH.sub.3                                                                          H          C.sub.2 H.sub.5                                                                        (C.sub.2 H.sub.4 O).sub.3 C.sub.2                                              H.sub.5   navy                              10 CN        CH.sub.3                                                                          m-Cl       C.sub.2 H.sub.5                                                                        (C.sub.2 H.sub.4 O).sub.2 CH.sub.3                                                       reddish blue                      11 CN        CH.sub.3                                                                          p-Cl       C.sub.2 H.sub.5                                                                        (C.sub.2 H.sub.4 O).sub.2 CH.sub.3                                                       reddish blue                      12 CN        CH.sub.3                                                                          m-SO.sub.2 N(CH.sub.3).sub.2                                                              C.sub.2 H.sub.5                                                                        (C.sub.2 H.sub.4 O).sub.2 CH.sub.3                                                       reddish blue                      13 CN        CH.sub.3                                                                          m-SO.sub.2 N(CH.sub.3).sub.2                                                              C.sub.2 H.sub.5                                                                        (C.sub.2 H.sub.4 O).sub.3 CH.sub.3                                                       reddish blue                      14 CN        CH.sub.3                                                                          p-OCH.sub.3                                                                               C.sub.2 H.sub.5                                                                        (C.sub.2 H.sub.4 O).sub.2 C.sub.2                                              H.sub.5   reddish blue                      15 CO.sub.2 CH.sub.3                                                                        CH.sub.3                                                                          H          C.sub.2 H.sub.5                                                                        (C.sub.2 H.sub.4 O).sub.2 C.sub.2                                              H.sub.5   bluish violet                     16 CO.sub.2 C.sub.2 H.sub.5                                                                 CH.sub.3                                                                          H          C.sub.2 H.sub.5                                                                        (C.sub.2 H.sub.4 O).sub.2 CH.sub.3                                                       bluish violet                     17 CN        Cl H          C.sub.2 H.sub.5                                                                        (C.sub.2 H.sub.4 O).sub.2 CH.sub.3                                                       navy                              18 CN        Cl H          C.sub.2 H.sub.5                                                                        (C.sub.2 H.sub.4 O).sub.2 C.sub.2                                              H.sub.5   navy                              19 CN        Cl H          C.sub.3 H.sub.6 OCH.sub.3                                                              (C.sub.2 H.sub.4 O).sub.2 C.sub.2                                              H.sub.5   navy                              20 CN        H  H          C.sub.3 H.sub.6 OCH.sub.3                                                              (C.sub.2 H.sub.4 O).sub.2 C.sub.2                                              H.sub.5   reddish blue                      21 CHO       H  H          C.sub.3 H.sub.6 OCH.sub.3                                                              (C.sub.2 H.sub.4 O).sub.2 C.sub.2                                              H.sub.5   blue                              22 CHO       H  H          C.sub.2 H.sub.5                                                                        (C.sub.2 H.sub.4 O).sub.2 C.sub.2                                              H.sub.5   blue                              23 CN        C.sub.2 H.sub.5                                                                   H          C.sub.2 H.sub.5                                                                        (C.sub.2 H.sub.4 O).sub.2 CH.sub.3                                                       reddish blue                      24 CHO       Cl H          C.sub.2 H.sub.5                                                                        (C.sub.2 H.sub.4 O).sub.2 CH.sub.3                                                       blue                              25 CHO       Cl H          C.sub.2 H.sub.5                                                                        (C.sub.2 H.sub.4 O).sub.2 C.sub.2                                              H.sub.5   blue                              26 CHO       Cl H          C.sub.2 H.sub.5                                                                        (C.sub.2 H.sub.4 O).sub.3 CH.sub.3                                                       blue                              27 CHO       Cl H          C.sub.2 H.sub.5                                                                        (C.sub. 2 H.sub.4 O).sub.3 C.sub.2                                             H.sub.5   blue                              28 CHO       Cl H          C.sub.3 H.sub.7 (n)                                                                    (C.sub.2 H.sub.4 O).sub.2 CH.sub.3                                                       blue                              29 CHO       Cl H          C.sub.2 H.sub.5                                                                        C.sub.3 H.sub.6 OC.sub.2 H.sub.4                                               OCH.sub.3 blue                              30 CHO       Cl H          C.sub.2 H.sub.5                                                                        C.sub.3 H.sub.6 OC.sub.2 H.sub.4                                               OC.sub.2 H.sub.5                                                                         blue                              31 CHO       Cl H          CH.sub.3                                                                               C.sub.3 H.sub.6 OC.sub.2 H.sub.4                                               OC.sub.2 H.sub.5                                                                         blue                              32 CHO       Cl H          CH.sub.3                                                                               C.sub.3 H.sub.6 OC.sub.2 H.sub.4                                               OCH.sub.3 blue                              33 CHO       Cl H          CH.sub.3                                                                               (C.sub.2 H.sub.4 O).sub.3 C.sub.2                                              H.sub.5   blue                              34 CHO       Cl H          C.sub.3 H.sub.7 (n)                                                                    (C.sub.2 H.sub.4 O).sub.3 CH.sub.3                                                       blue                              35 CHO       Cl H          C.sub.2 H.sub.4 OC.sub.4 H.sub.9 (n)                                                   (C.sub.2 H.sub.4 O).sub.3 C.sub.2                                              H.sub.5   blue                              36 CHO       Cl H          C.sub.2 H.sub.4 OCH.sub.3                                                              (C.sub.2 H.sub.4 O).sub.2 C.sub.2                                              H.sub.5   blue                              37 CHO       Cl H          C.sub.3 H.sub.6 OC.sub.3 H.sub.7                                                       (C.sub.2 H.sub.4 O).sub.3 C.sub.2                                              H.sub.5   blue                              38 CHO       Cl H          C.sub.2 H.sub.4 OC.sub.2 H.sub.5                                                       (C.sub.2 H.sub.4 O).sub.2 C.sub.2                                              H.sub.5   blue                              39 CHO       Cl H          C.sub.3 H.sub.6 OC.sub.2 H.sub.5                                                       (C.sub.2 H.sub.4 O).sub.3 C.sub.2                                              H.sub.5   blue                              40 CHO       Cl H          C.sub.3 H.sub.6 OC.sub.2 H.sub.5                                                       (C.sub.2 H.sub.4 O).sub.3 CH.sub.3                                                       blue                              41 CHO       Cl H          CH(CH.sub.3).sub.2                                                                     (C.sub.2 H.sub.4 O).sub.2 CH.sub.3                                                       blue                              42 CHO       Cl m-SO.sub.2 N(CH.sub.3).sub.2                                                              C.sub.2 H.sub.5                                                                        (C.sub.2 H.sub.4 O).sub.2 CH.sub.3                                                       blue                              43 CHO       Cl m-SO.sub.2 N(C.sub.2 H.sub.4 OCH.sub.3).sub.2                                             C.sub.2 H.sub.5                                                                        (C.sub.2 H.sub.4 O).sub.2 CH.sub.3                                                       blue                              44 CHO       Cl m-Cl       C.sub.2 H.sub.5                                                                        (C.sub.2 H.sub.4 O).sub.2 CH.sub.3                                                       blue                              45 CHO       Cl p-Cl       C.sub.2 H.sub.5                                                                        (C.sub.2 H.sub.4 O).sub.2 CH.sub.3                                                       blue                              46 CHO       Cl p-Cl       C.sub.2 H.sub.5                                                                        (C.sub.2 H.sub.4 O).sub.3 CH.sub.3                                                       blue                              47                                                                                 ##STR12##                                                                               Cl H          C.sub.2 H.sub.5                                                                        (C.sub.2 H.sub.4 O).sub.2 CH                                                             greenish blue                     48                                                                                 ##STR13##                                                                               Cl H          C.sub.2 H.sub.5                                                                        (C.sub.2 H.sub.4 O).sub.3 C.sub.2                                              H.sub.5   greenish blue                     __________________________________________________________________________

                                      TABLE 2                                      __________________________________________________________________________      ##STR14##                                                                     Ex. No.                                                                             R.sup.1                                                                             R.sup.2                                                                            X   R.sup.5  R.sup.6   Hue                                       __________________________________________________________________________     49   CN   CH.sub.3                                                                           H   CH.sub.3 C.sub.3 H.sub.6 OC.sub.2 H.sub.4 OCH.sub.3                                               blue                                      50   CN   CH.sub.3                                                                           H   C.sub.2 H.sub.5                                                                         C.sub.3 H.sub.6 OC.sub.2 H.sub.4 OCH.sub.3                                               blue                                      51   CN   CH.sub.3                                                                           H   C.sub.2 H.sub.5                                                                         C.sub.3 H.sub.6 OC.sub.2 H.sub.4 OCH.sub.3                                               blue                                      52   CN   CH.sub.3                                                                           H   C.sub.2 H.sub.5                                                                         (C.sub.2 H.sub.4 O).sub.2 CH.sub.3                                                       blue                                      53   CN   CH.sub.3                                                                           H   C.sub.2 H.sub.5                                                                         (C.sub.2 H.sub.4 O).sub.3 CH.sub.3                                                       blue                                      54   CN   CH.sub.3                                                                           H   C.sub.2 H.sub.5                                                                         (C.sub.2 H.sub.4 O).sub.2 C.sub.2 H.sub.5                                                blue                                      55   CN   CH.sub.3                                                                           H   C.sub.2 H.sub.5                                                                         (C.sub.2 H.sub.4 O).sub.3 C.sub.2 H.sub.5                                                blue                                      56   CN   CH.sub.3                                                                           H   C.sub.2 H.sub.5                                                                         (C.sub.2 H.sub.4 O).sub.2 CH.sub.3                                                       blue                                      57   CN   CH.sub.3                                                                           H   C.sub.3 H.sub.7                                                                         (C.sub.2 H.sub.4 O).sub.2 CH.sub.3                                                       blue                                      58   CN   CH.sub.3                                                                           H   C.sub.2 H.sub.5                                                                         (C.sub.2 H.sub.4 O).sub.3 CH.sub.3                                                       blue                                      59   CN   CH.sub.3                                                                           H   C.sub.3 H.sub.7                                                                         (C.sub.2 H.sub.4 O).sub.3 CH.sub.3                                                       blue                                      60   CN   CH.sub.3                                                                           H   C.sub.2 H.sub.5                                                                         (C.sub.2 H.sub.4 O).sub.2 C.sub.2 H.sub.5                                                blue                                      61   CO.sub.2 CH.sub.3                                                                   CH.sub.3                                                                           H   C.sub.2 H.sub.5                                                                         (C.sub.2 H.sub.4 O).sub.2 C.sub.2 H.sub.5                                                blue                                      62   CO.sub.2 C.sub.2 H.sub.5                                                            CH.sub.3                                                                           H   C.sub.2 H.sub.5                                                                         (C.sub.2 H.sub.4 O).sub.2 CH.sub.3                                                       blue                                      63   CN   CH.sub.3                                                                           H   C.sub.2 H.sub.5                                                                         (C.sub.2 H.sub.4 O).sub.3 C.sub.2 H.sub.5                                                blue                                      64   CHO  Cl  H   C.sub.3 H.sub.6 OC.sub.2 H.sub.5                                                        (C.sub.2 H.sub.4 O).sub.3 C.sub.2 H.sub.                                                 bluish green                              65   CN   Cl  H   C.sub.2 H.sub.5                                                                         (C.sub.2 H.sub.4 O).sub.2 C.sub.2 H.sub.5                                                blue                                      66   CN   Cl  H   C.sub.3 H.sub.6 OCH.sub.3                                                               (C.sub.2 H.sub.4 O).sub.2 C.sub.2 H.sub.5                                                blue                                      67   CN   C.sub.6 H.sub.5                                                                    H   C.sub.3 H.sub.6 OCH.sub.3                                                               (C.sub.2 H.sub.4 O).sub.2 C.sub.2 H.sub.5                                                blue                                      68   CHO  H   H   C.sub.3 H.sub.6 OCH.sub.3                                                               (C.sub.2 H.sub.4 O).sub.3 CH.sub.3                                                       greenish blue                             69   CHO  H   H   C.sub.2 H.sub.5                                                                         (C.sub.2 H.sub.4 O).sub.3 CH.sub.3                                                       greenish blue                             70   CN   C.sub.2 H.sub.5                                                                    H   C.sub.2 H.sub.5                                                                         (C.sub.2 H.sub.4 O).sub.2 CH.sub.3                                                       blue                                      71   CHO  Cl  H   C.sub.2 H.sub.5                                                                         (C.sub.2 H.sub.4 O).sub.2 CH.sub.3                                                       turquoise                                 72   CHO  Cl  H   C.sub.2 H.sub.5                                                                         (C.sub.2 H.sub.4 O).sub.2 C.sub.2 H.sub.5                                                bluish green                              73   CHO  Cl  H   C.sub.2 H.sub.5                                                                         (C.sub.2 H.sub.4 O).sub.3 CH.sub.3                                                       bluish green                              74   CHO  Cl  H   C.sub.2 H.sub.5                                                                         (C.sub.2 H.sub.4 O).sub.3 C.sub.2 H.sub.5                                                bluish green                              75   CHO  Cl  H   C.sub.3 H.sub.7 (n)                                                                     (C.sub.2 H.sub.4 O).sub.2 CH.sub.3                                                       bluish green                              76   CHO  Cl  H   C.sub.2 H.sub.5                                                                         C.sub.3 H.sub.6 OC.sub.2 H.sub.4 OCH.sub.3                                               bluish green                              77   CHO  Cl  H   C.sub.2 H.sub.5                                                                         C.sub.3 H.sub.6 OC.sub.2 H.sub.4 OC.sub.2                                                bluish green                              78   CHO  Cl  H   CH.sub.3 C.sub.3 H.sub.6 OC.sub.2 H.sub.4 OC.sub.2                                      H.sub.5   bluish green                              79   CHO  Cl  2-CH.sub.3                                                                         CH.sub.3 C.sub.3 H.sub.6 OC.sub.2 H.sub.4 OCH.sub.3                                               bluish green                              80   CHO  Cl  H   C.sub.2 H.sub.5                                                                         (C.sub.2 H.sub.4 O).sub.3 C.sub.2 H.sub.5                                                bluish green                              81   CHO  Cl  H   C.sub.3 H.sub.7 (n)                                                                     (C.sub.2 H.sub.4 O).sub.3 CH.sub.3                                                       bluish green                              82   CHO  Cl  H   C.sub.2 H.sub.4 OC.sub.4 H.sub.9 (n)                                                    (C.sub.2 H.sub.4 O).sub.3 C.sub.2 H.sub.5                                                bluish green                              83   CHO  Cl  H   C.sub.2 H.sub.4 OCH.sub.3                                                               (C.sub.2 H.sub.4 O).sub.2 C.sub.2 H.sub.5                                                bluish green                              84   CHO  Cl  H   C.sub.2 H.sub.4 OC.sub.3 H.sub.7 (n)                                                    (C.sub.2 H.sub.4 O).sub.3 C.sub.2 H.sub.5                                                bluish green                              85   CHO  Cl  H   C.sub.2 H.sub.4 OC.sub.2 H.sub.5                                                        (C.sub.2 H.sub.4 O).sub.2 C.sub.2 H.sub.5                                                bluish green                              86   CHO  Cl  H   C.sub.3 H.sub.6 OC.sub.2 H.sub.5                                                        (C.sub.2 H.sub.4 O).sub.3 CH.sub.3                                                       bluish green                              87   CHO  Cl  H   C.sub.2 H.sub.4 OC.sub.2 H.sub.5                                                        (C.sub.2 H.sub.4 O).sub.3 CH.sub.3                                                       bluish green                              88   CHO  Cl  H   CH(CH.sub.3).sub.2                                                                      (C.sub.2 H.sub.4 O).sub.2 CH.sub.3                                                       bluish green                              89   CHO  Cl  H   C.sub.2 H.sub.5                                                                         (C.sub.2 H.sub.4 O).sub.2 CH.sub.3                                                       bluish green                              90   CHO  Cl  H   C.sub.3 H.sub.6 OC.sub.3 H.sub.7 (n)                                                    (C.sub.2 H.sub.4 O).sub.3 C.sub.2 H.sub.5                                                turquoise                                 91   CHO  Cl  H   C.sub.3 H.sub.7                                                                         (C.sub.2 H.sub.4 O).sub.2 CH.sub.3                                                       turquoise                                 92   CHO  OC.sub.2 H.sub.5                                                                   H   C.sub.2 H.sub.5                                                                         (C.sub.2 H.sub.4 O).sub.2 CH.sub.3                                                       turquoise                                 93   CHO  OC.sub.2 H.sub.5                                                                   H   C.sub.3 H.sub.7 (n)                                                                     (C.sub.2 H.sub.4 O).sub.2 CH.sub.3                                                       turquoise                                 94   CHO  H   H   C.sub.3 H.sub.7                                                                         (C.sub.2 H.sub.4 O).sub.3 CH.sub.3                                                       bluish green                              95   CO.sub.2 CH.sub.3                                                                   CH.sub.3                                                                           H   C.sub.2 H.sub.5                                                                         (C.sub.2 H.sub.4 O).sub.3 CH.sub.3                                                       blue                                      96   CO.sub.2 CH.sub.3                                                                   C.sub.2 H.sub.5                                                                    H   C.sub.2 H.sub.5                                                                         (C.sub.2 H.sub.4 O).sub.3 CH.sub.3                                                       blue                                      __________________________________________________________________________

                                      TABLE 3                                      __________________________________________________________________________      ##STR15##                                                                     Ex. No.                                                                             R.sup.1    R.sup.2                                                                             R.sup.3                                                                             R.sup.4                                                                               R.sup.5 R.sup.6   Hue                         __________________________________________________________________________      97  CH.sub.3 O.sub.2 C                                                                        CH.sub.3                                                                            CN                                                                                   ##STR16##                                                                            C.sub.4 H.sub.8 OCH.sub.3                                                              (C.sub.2 H.sub.4 O).sub.3                                                      C.sub.2 H.sub.5                                                                          blue                         98                                                                                  ##STR17## H    CN   C.sub.6 H.sub.5                                                                       C.sub.3 H.sub.6 OCH.sub.3                                                              (C.sub.2 H.sub.4 O).sub.3                                                      CH.sub.3  blue                         99  C.sub.2 H.sub.5 O.sub.2 C                                                                 C.sub.2 H.sub.5 O.sub.2 C                                                           CN   C.sub.6 H.sub.5                                                                       C.sub.3 H.sub.7 (n)                                                                    C.sub.3 H.sub.6 OC.sub.2                                                                 reddish blue                100  C.sub.2 H.sub.5 O.sub.2 C                                                                 C.sub.2 H.sub.5                                                                     CN                                                                                   ##STR18##                                                                            C.sub.3 H.sub.7 (n)                                                                    C.sub.3 H.sub.6 OC.sub.2                                                                 blueb.5                     101  CN         CH.sub.3                                                                            CN   C.sub.6 H.sub.5                                                                       C.sub.3 H.sub.7 (n)                                                                    (C.sub.2 H.sub.4 O).sub.2                                                      CH.sub.3  reddish blue                102  CN         CH.sub.3                                                                            CN   C.sub.6 H.sub.5                                                                       C.sub.3 H.sub.7 (l)                                                                    (C.sub.2 H.sub.4 O).sub.2                                                      CH.sub.3  reddish blue                103  CN         CH.sub.3                                                                            CN   C.sub.6 H.sub.5                                                                       C.sub.4 H.sub.9 (n)                                                                    (C.sub.2 H.sub.4 O).sub.2                                                      CH.sub.3  reddish blue                104  CN         CH.sub.3                                                                            CN                                                                                   ##STR19##                                                                            C.sub.3 H.sub.7 (n)                                                                    (C.sub.2 H.sub.4 O).sub.2                                                      CH.sub.3  blue                        105  CN         CH.sub.3                                                                            CN                                                                                   ##STR20##                                                                            C.sub.3 H.sub.7 (n)                                                                     ##STR21##                                                                               blue                        106  C.sub.2 H.sub.5 O.sub.2 C                                                                 C.sub.2 H.sub. 5 O.sub.2 C                                                          CN   C.sub.6 H.sub.5                                                                       C.sub.2 H.sub.4 OC.sub.3 H.sub.7                                                       C.sub.3 H.sub.6 OC.sub.2 H.sub.4                                               OC.sub.2 H.sub.5                                                                         reddish blue                107  C.sub.2 H.sub.5 O.sub.2 C                                                                 CH.sub.3                                                                            CO.sub.2 C.sub.2 H.sub.5                                                            C.sub.6 H.sub.5                                                                       C.sub.2 H.sub.4 OC.sub.4 H.sub.9                                                       C.sub.3 H.sub.6 OC.sub.3 H.sub.4                                               OC.sub.2 H.sub.5                                                                         violet                      108  C.sub.2 H.sub.5 O.sub.2 C                                                                 CH.sub.3                                                                            CO.sub.2 C.sub.2 H.sub.5                                                            C.sub.6 H.sub.5                                                                       C.sub.3 H.sub.7 (n)                                                                    C.sub.3 H.sub.6 OC.sub.2                                                                 violet5                     109  CHO        CH.sub.3                                                                            CN   C.sub.6 H.sub.5                                                                       C.sub.2 H.sub.5                                                                        C.sub.2 H.sub.4 OC.sub.2 H.sub.4                                               OCH.sub.3 blue                        110  CHO        CH.sub.3                                                                            CN   C.sub.6 H.sub.5                                                                       C.sub.2 H.sub.5                                                                        (C.sub.2 H.sub.4 O).sub.3                                                      C.sub.2 H.sub.5                                                                          blue                        111  CHO        CH.sub.3                                                                            CN   C.sub.6 H.sub.5                                                                       C.sub.3 H.sub.6 OCH.sub.3                                                              (C.sub.2 H.sub.4 O).sub.2                                                      C.sub.2 H.sub.5                                                                          blue                        __________________________________________________________________________

                  TABLE 4                                                          ______________________________________                                          ##STR22##                                                                                                          λ.sub.max                          Ex. No.   L.sup.1   L.sup.2 L.sup.3  [nm]                                      ______________________________________                                         112       CO.sub.2 CH.sub.3                                                                        CH.sub.3                                                                                ##STR23##                                                                              580                                       113       CO.sub.2 CH.sub.3                                                                        CH.sub.3                                                                                ##STR24##                                                                              594                                       114       CHO       Cl                                                                                      ##STR25##                                                                              638                                       115       CHO       Cl                                                                                      ##STR26##                                                                              592                                       116       CHO       Cl      C.sub.6 H.sub.5                                                                         606                                       117       CN        CH.sub.3                                                                                ##STR27##                                                                              609                                       ______________________________________                                     

We claim:
 1. A thiopheneazo dye of the formula I ##STR28## where R¹ is cyano or formyl,R² is methyl, phenyl or chlorine, R³ is cyano, R⁴ is C₁ -C₈ -alkyl, cyclohexyl, phenoxy-C₁ -C₄ -alkyl;, unsubstituted phenyl or thienyl, R⁵ is C₁ -C₄ -alkyl, C₃ -C₇ -alkyl whose alkyl chain is interrupted by 1 or 2 oxygen atoms, each oxygen atom being attached to only a carbon atom, or C₁ -C₄ -alkoxy and R⁶ is phenylethyl, or C₃ -C₁₂ -alkyl whose alkyl chain is interrupted by from 1 to 4 oxygen atoms, each oxygen atom being attached to only a carbon atom, or said interrupted C₃ -C₁₂ -alkyl substituted by phenyl or phenoxy,with the proviso that, when R⁵ and R⁶ are each oxygen-interrupted alkyl, R⁶ has 2 or more carbon atoms more than R⁵.
 2. A thiophene dye as claimed in claim 1, wherein R⁶ is methoxyethyl, methoxypropyl or 3,5-dioxaoctyl.
 3. A thiophene dye as claimed in claim 2, wherein R¹ is formyl and R² is methyl or phenyl.
 4. A thiophene dye as claimed in claim 1, wherein R¹ is formyl and R² is methyl or phenyl.
 5. A thiopheneazo dye as claimed in claim 1, whereinR² is methyl or chlorine, R³ is cyano, R⁴ is phenyl, 2-thienyl or 3-thienyl, R⁵ is C₁ -C₄ -alkyl and R⁶ is C₃ -C₉ -alkyl whose alkyl chain is interrupted by from 1 to 3 oxygen atoms, or said interrupted C₃ -C₉ -alkyl substituted by phenoxy.
 6. A method of dyeing textile fibers comprising applying thereto a thiopheneazo dye as claimed in claim
 1. 